WebGestalt2: an Updated and Expanded Version of the Web-based Gene Set Analysis Toolkit.

Background Functional enrichment analysis has become a popular approach for the interpretation of gene lists derived from large scale genomic, transcriptomic, and proteomic studies. Many software tools have been developed for this analysis, including our previously published Web-based Gene Set Enrichment Analysis Toolkit (WebGestalt) [1]. Major differences among existing tools include: 1) the statistical test used for the enrichment analysis; 2) supported organisms; 3) supported input ID types; 4) coverage of functional categories; and 5) presentation of the output results. We have made improvements in the above areas in the updated and expanded version, WebGestalt2.